You seem to need information about how the game works.
That's not 2 FCs owning a combined 24 houses. It's impossible for a single FC to own more than one house. That's 24 different FCs owning one house each. If you're going "but the FC tag!", FC tags are not unique. Multiple FCs can use the same tag.
What is possible is for those 24 FCs to be led by a single player who is paying for 3 service accounts and has created 8 characters on each account with each character leading a different one of those FCs. The game itself doesn't know what real person owns an account. To it, each service account represents a separate person. Actual account owner identity will be tracked by the accounts and billing system outside of the game programming.
Is that greedy? It depends on when the player established those FCs and the houses purchased.
If it was done on or before Jan.29, 2018, then no. The game allowed it until that date.
If the FC was created on or after Jan. 30th, 2018 or it was a second FC house purchase on the account then yes, it's greed and exploiting loopholes in the game's system.
Unfortunately, it's outside GM authority to enforce the housing rules posted on the Lodestone just as it's outside their authority to handle bot related issues. Unlike bots, SE evidently didn't set up a team to handle housing ownership exploits so the player base has no recourse when someone chooses to exploit the system.
Except there are multiple individual players who do have access to workshops because they set up shell FCs to get it.
It's not like legitimate FCs can make all that much gil off a workshop anymore with the number of individual players running those multiple workshops for personal profit. SE might as well release workshops to all players in that case and find some other perks for FCs.
I think you need to look again. This isn't early 2019 anymore.
They've got a major housing update already in the works. We know it's coming after every world has completed its Ishgard Restoration so hopefully that means 5.5.
At this point we need patience. It doesn't hurt to continue to give feedback about changes we'd like to see but we need to stop with the "you need to do something, SE". They are. Once the new update is released, we can give feedback on any problems we still see.